It is possible to segment players by Average Session Length

There is an automatically configured Generic Metric that you can use if you are interested in just players who have played in the last 7 days.

If you want to look at overall Average Session Length you need to create a new Derived Metric.

Start by creating a new Manual Segment and give it a name and description. 

We will need to create a new player metric containing the Average Session Length, so select the Derived metric type and click on the settings icon to open the derived metrics manager.

Navigate to the Add tab and create your new Average Session Length = Total Time Played Ms / Total Sessions Played metric.

Press the Save button

You will notice that your new metric has a warning icon against it in the Derived Metrics Manager. This warning will clear once some data has been been received for the new metric.

Return to the segment manager and enter your segment conditions. 

( 10 mins = 1000MS * 60 seconds * 10 mins => 600,000Ms)

You can then use this Segment to make comparisons to other cohorts using Measure charts and many of the Analyze tools.